1. Field of the Invention
The present invention generally relates to a self-light-emitting device (also referred to as an EL device). In particular, the present invention relates to such a self-light emitting device in which an EL element, which is constructed of an anode, a cathode, and a light emitting organic material (hereinafter, referred to as organic EL material) with which EL (electro luminescence) is obtained, is sandwiched therebetween, is formed on an insulator, and to a method of manufacturing electric equipment having the self-light-emitting device as a display portion (display or display monitor). Note that in this specification, a description will be made of an EL display device as the above stated self-light-emitting device.
2. Description of the Related Art
In recent years, the development of display devices using an EL element (EL display device) as a self-light-emitting element which utilizes the EL phenomenon of light emitting organic material has been advancing. The EL display device is a self-light-emitting device, and therefore it doesn't need a back light such as that of a liquid crystal display device. In addition, the EL display device has a wide angle of view. As a result, the El display device is looked upon as promising as a display portion of electric equipment.
EL display devices are classified into two: a passive type (simple matrix type); and an active type (active matrix type), both of which have been actively developed. Particularly, the active matrix EL display device is attracting attention these days. With regard to organic EL materials to be an EL layer which can be said to be the center of an EL element, low molecular weight organic EL materials and high molecular (polymer) organic EL materials have been studied. The low molecular weight organic EL materials are formed by vapor deposition or the like, while the high molecular organic EL materials are formed through a coating using a spinner.
With respect to both the low molecular weight organic EL material and the high molecular (polymer) organic EL materials, when the surface on which the EL material is formed is not planarized, there is a problem in that the thickness of the formed EL material can not be even.
Further, in case that the thickness of the EL layer is not even and the EL layer is partly not formed at a step portion, when an EL element formed of a cathode, the EL layer, and an anode is formed, the cathode and the anode are short-circuited.
When the cathode and the anode are short-circuited, electric current intensively flows between the cathode and the anode, and almost no electric current flows through the EL layer, which makes the EL layer not to emit light.